1. Field of the Invention
The present invention relates to a thin panel display, for example for a vehicle, and more particularly to a holographic thin panel display that provides an apparent depth to the indicia realized, when appropriately illuminated, to accomodate the vision of the viewer.
2. Description of Related Art
Various form of panel displays are known for providing indicia representative of the operating condition of a particular system or process. A common form of display is that utilized in aircraft and vehicles to provide an indication of the various operating characteristics that are necessary for the operator to observe, such as disclosed in U.S. Pat. Nos. 3,940,204 and 4,447,128. Frequently, the location of the panel and the distance to the operator requires an adjustment to take into consideration the focusing ability of the operator. This unique problem can occur when the operator is basically farsighted and has difficulty in focusing on a relatively near display. As the human eye ages, it loses its flexibility to focus on nearby objects and thereby defeats the capacity of prior displays that were to be mounted, for example, on the steering wheel hub of a car.
Federal regulations to increase the fuel efficiency of cars have resulted in more compact cars with limited interior space. The various fuel emission controls have further reduced the space available in the engine. This is further complicated by the recent aerodynamic body configurations provided on autos to reduce drag. As a result, the provision for space in an automobile of a compact design is a critical design factor.
The prior art is still striving to provide improved panel displays and in the automotive field, they are attempting to provide thin improved panel displays that will accomodate the focusing ability of a driver.